Modern digital television (DTV) systems are able to provide interaction between an end-user and a service provider (e.g., a television broadcaster) through the use of a return path. For example, a dialup modem, a high-speed Internet connection, or other mechanisms can be used for the return path to service providers with unidirectional networks, such as satellite or antenna broadcast. Other service providers may use bidirectional network links to incorporate a return path, such as coaxial and fiber optic cables. A DTV receiver that incorporates a return path may be referred to as a “connected DTV.”
A DTV receiver typically includes an ATSC (Advanced Television Systems Committee) tuner and/or a QAM (quadrature amplitude modulation) tuner for receiving over-the-air television signals or cable television signals, respectively. To facilitate the reception of numerous channels, most DTV receivers are equipped with a channel auto-scanning function that automatically scans each channel to detect the presence of program content when such DTV receivers are turned on for the first time or after a re-boot.
DTV broadcast stations generally broadcast information such as their call letters and a “virtual” channel number as background data, and the radio frequency (RF) channel they use might be different from the virtual channel number. For example, a channel might be advertised as “39-1” (e.g., the virtual channel number) but may actually use RF channel 42. A DTV receiver typically matches the RF channels and virtual channels by scanning all of the available RF channel frequencies and checking each of the RF channel frequencies for a signal. If a signal is found, the DTV receiver can memorize the advertised channel number. This scanning process can take a long time and usually does not provide the DTV user with additional information about the channel unless the user tunes to that channel and waits for a data stream to be acquired.